1. Field of the Invention
The invention pertains to auxiliary knobs used in conjunction with cameras focused by rotating a knob associated with rack and pinion focusing systems. The auxiliary knob improves handling, access and operating characteristics.
2. Description of the Related Art
Photographic cameras of the professional type as mounted upon a tripod or other fixed structure often include a focusing mechanism for adjusting the focus. Such focusing systems often consist of rack and pinion type drives wherein the rotation of a focusing knob rotates a gear meshing with a rack which permits the lens system to be adjusted.
Because of size and design limitations, access to such focusing knobs may be limited. With many camera designs using focusing knobs the knobs are relatively small in diameter, which requires a relatively tight grip upon the knob to produce the necessary torque to adjust the lenses.
In addition to requiring relatively high torque for camera focusing, the conventional knobs are often mounted so close to the camera body, and levers and operating mechanism mounted upon the camera body, that the fingers often engage the camera body during operation of the focusing knob, and women will often break fingernails due to the proximity of the knob to the camera body and camera body components. Even more seriously, the size of the focusing knobs, the frequency of usage, and the torque required to produce focusing, may cause medical problems of the wrist, hand, fingers or forearm, and may cause carpal tunnel and arthritis symptoms.